AbstractThe Guillain-Barré syndrome is associated with acute polyradiculoneuritis for almost one century. Its spectrum has considerably been enlarged since its first description. It now includes pure motor or sensory syndromes, focal forms, demyelinating and axonal neurophysiological features that characterise excitability dysfunctions, and immunological differentiations. We can hope that this improved classification will facilitate development of treatment innovations for a condition that is still a life-threatening condition with a severe functional prognosis in a significant proportion of cases.